1. Biotechnology: Its applications
It includes therapeutics,
diagnostics, genetically modified
crops for agriculture, processed
food, bioremediation, water
treatment and energy
production.
2.
3. What are the three critical
research areas of biotechnology?
Providing the best catalyst in the form
of improved organism usually a
microbe or pure enzyme.
Creating optimal conditions through
engineering for a catalyst to act.
Downstream processing technologies
to purify the protein/ organic
compound.
4.
5.
6. What are the three ways for
increasing food production?
Agro-chemical based agriculture
(fertiliser and pesticides)
Organic agriculture (Organic
farming i.e. use of bio fertilisers
and biocides)
Genetically engineered crop-based
agriculture.
9. Advantages of genetically
modified plants
It has made crops more tolerant to
abiotic stresses like cold, draught,
salinity, heat etc.
It has made crops resistant to pest.
It has helped to reduce post harvest
losses.
It has increased efficiency of mineral
usage by plants.
10. Enhanced the nutrient value of food.
E.g. Vit.’A’ enriched rice.
Genetic modification has been used to
create tailor-made plants to supply
alternatives resources to industries, in
the form of starches, fuels and
pharmaceuticals.
11. Bt cotton:
Some strains of Bacillus thuringiensis
produces crystal proteins called Cry
proteins that are toxic to the larvae of
insects like tobacco budworm, army worm,
beetles, flies and mosquitoes.
The Cry proteins exist as inactive protoxins
but once an insect ingest the inactive toxin,
it is converted into an active form of toxin
due to the alkaline pH of the gut which
solubilise the crystals.
12. The activated toxins bind to the surface of
midgut cells and create pores that cause cell
swelling and lysis and finally death of the insect
larva.
Bt toxin genes were isolated from Bacillus
thuringiensis and incorporated into several crop
plants like cotton, corn, rice, tomato, soya bean,
potato.
These are called Bt cotton, Bt corn, Bt rice, Bt
tomato, Bt soya bean and Bt potato.
There are different Cry genes. E.g. Cry IAc and
Cry IAb: Control cotton boll worms. Cry IAb:
controls corn borer.
16. Pest resistant plants:
A nematode Meloidegyne incognitia infects the
roots of tobacco plants and causes a great
reduction in yield.
This was prevented by a process called RNA
interference (RNAi)
RNAi takes place in all eukaryotic organisms as a
method of cellular defence. This method include
silencing of a specific mRNA due to a
complementary dsRNA molecules that binds to
and prevent translation of the mRNA (silencing)
17. Using Agro bacterium vectors, nematode specific
genes were introduced into the host plant.
The introduction of DNA was in such a way that
it produces both sense and antisense RNA in the
host cells.
These two RNA’s being complementary to each
other formed a double stranded (dsRNA) that
initiated RNAi and thus, silenced the specific
mRNA of the nematode.
As a result of this parasite cannot live in the
transgenic host and the transgenic plant
therefore protected from the pest.
18. Host plant generated dsRNA triggers protection against
nematode infestation:
(a) Roots of a typical control plants; (b) transgenic plants
roots 5 days after deliberate infections of nematode but
protected through novel mechanism.
19. Biotechnological application in
medicine
Genetically engineered insulin:
Human insulin consists of two short
polypeptide chains: Chain A and Chain B,
linked by disulphide bridges.
Insulin is secreted as prohormone which has
to be processed, before it becomes a mature
and functional hormone.
20. The prohormone contains another
polypeptide, called C-peptide, which is
removed during maturation.
In1983, Eli Lilly, an American company,
prepared two DNA sequences coding for
Chain A and Chain B of human insulin and
introduced them into the plasmid of E.coli
to produce insulin.
The two chains produced were extracted
and combined by creating disulphide
bridges.
21.
22. Gene therapy:
Gene therapy is a collection of methods that
allows correction of a gene defect that has been
diagnosed in a child/ embryo.
In this case genes are inserted into a person’s cells
and tissues to treat a disease.
The first clinical gene therapy was given in 1990 to
a four year old girl with adenosine de aminase
(ADA) deficiency. This enzyme is crucial for the
immune system to function.
This is due to the deletion of the gene for
adenosine de aminase.
23. In some children it can be cured by bone marrow
transplantation or by enzyme replacement therapy,
in which functional ADA is given to patient by
injection. But these processes are not permanent
for cure of disease.
Thus first step towards the gene therapy include
culture of lymphocytes from the blood of patient
outside the body. A functional ADA cDNA, using a
retrovirus vector is introduced into these
lymphocytes and again returned it back to the
patient body. This method could be a permanent
cure.
24. Molecular diagnosis:
Recombinant DNA technology, Polymerase
Chain Reaction (PCR) and Enzyme linked
Immuno-Sorbent Assay (ELISA) are different
molecular diagnosis.
PCR is now routinely used to detect HIV in
suspected AIDS patients. It is also used to
detect mutations in genes in suspected
cancer patient. It is also used to identify
many genetic disorders.
25. ELISA is based on the principle of
antigen-antibody interaction. Infection
by pathogen can be detected by the
presence of antigens (Proteins, glyco
proteins etc) or by detecting the
antibodies synthesised against the
pathogen.
26. Transgenic animals:
Animals that have had their DNA
manipulated to possess and
express an extra gene are called
transgenic animals. E.g.
Transgenic rats, rabbits, pigs,
sheep, cow, fish etc. Though 95%
of all existing transgenic animals
are mice.
27. Benefits of transgenic animals
Normal physiology and
development: Transgenic animals
can be specifically designed to
allow the study of how genes are
regulated and how they affect the
normal functions of the body and
its development.
28. Study of disease: Transgenic
animals are designed to increase
our understanding of how genes
contribute to the development of
disease.
29. Biological products: Transgenic animals that
produce useful biological compounds can be
created by introducing a portion of DNA
that codes for that product from other
organisms. E.g. α-1 antitrypsin, a human
protein is used to treat emphysema. The
first transgenic cow, Rose, produced the
human protein enriched milk, it contained
human alpha-lact albumin (2-4gm/l), a more
nutritionally balanced product for human
baby.
30. Vaccine safety: Transgenic mice are
being developed for use in testing the
safety of vaccine before they are used
on humans. E.g. Polio vaccine.
Chemical safety testing: Transgenic
animals with more sensitivity to toxic
substances are being developed to test
the toxicity of drugs; this will produce
the results in less time.
31. Ethical issues:
Genetic modification of organisms can
have unpredictable results when such
organisms are introduced into the
ecosystem. Therefore, Indian government
has set up organisations such as GEAC
(genetic Engineering Approval Committee)
which will make decision regarding the
validity of GM research and the safety of
introducing GM- organisms for public
services.
32. Bio piracy:
It is the term used to refer to the
use of bio-resource by multinational
companies and other organisations
without proper authorisation from
the countries and people concerned
without compensatory payment. To
prevent this some laws are made by
some nations.
